"The sun is setting right just over the top of Windsor Castle just behind them, it was just the most serene, beautiful light, they're in love, walking around this beautiful garden," Lubomirski said.
"I said 'just before you go in, let's sit down on these stairs', and she (Meghan) just slumped in between his legs.
"They were just laughing because they were joking about how they were exhausted and finally it was over."
Just two days ago, marking two years since they announced their engagement, the Duke and Duchess of Sussex posted a never before seen wedding portrait on their official Instagram page, which Mr Lubomirski said was an "outtake".
"This is an outtake from the Rose garden where we were given 3 minutes to take some informal pictures of the happy couple after the wedding reception," he wrote.
Mr Lubomirski also revealed how he came to shoot the couple in the first place, saying Kensington Palace called him on the day of the couple's engagement announcement asking if he was "interested in doing a project".
"Two weeks later, I was shooting the official engagement portraits of the Duke and Duchess of Sussex," he wrote.
"Kensington Palace called my phone, out of the blue, whilst I was sitting in a hospital waiting room, waiting for a family member to wake up after a 10 hour brain surgery, to ask if I would be interested in doing a project together."
His images of the couple's official engagement portraits were released in December 2017, showing Meghan and Harry on the grounds of Frogmore House in Windsor.
